Move all the component definitions for drivers to a single shared place,
include/acpi/acpi_drivers.h.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch is part of a larger patch series which will remove
the "char bus_id[20]" name string from struct device. The device
name is managed in the kobject anyway, and without any size
limitation, and just needlessly copied into "struct device".
To set and read the device name dev_name(dev) and dev_set_name(dev)
must be used. If your code uses static kobjects, which it shouldn't
do, "const char *init_name" can be used to statically provide the
name the registered device should have. At registration time, the
init_name field is cleared, to enforce the use of dev_name(dev) to
access the device name at a later time.
We need to get rid of all occurrences of bus_id in the entire tree
to be able to enable the new interface. Please apply this patch,
and possibly convert any remaining remaining occurrences of bus_id.
We want to submit a patch to -next, which will remove bus_id from
"struct device", to find the remaining pieces to convert, and finally
switch over to the new api, which will remove the 20 bytes array
and does no longer have a size limitation.
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-Off-By: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Len Brown <len.brown@intel.com>
ACPI_DB_ERROR and ACPI_DB_WARN were removed from ACPICA core.
So replace ACPI_DEBUG_PRINT((ACPI_DB_ERROR, ...) with printk(KERN_ERR PREFIX ...)
and ACPI_DEBUG_PRINT((ACPI_DB_WARN, ...) with printk(KERN_WARNING PREFIX ...)
We do not use ACPI_ERROR/ACPI_WARNING since they're not exported, see
-------------------------------------------------------------
commit 6468463abd
Author: Len Brown <len.brown@intel.com>
Date: Mon Jun 26 23:41:38 2006 -0400
ACPI: un-export ACPI_ERROR() -- use printk(KERN_ERR...)
Signed-off-by: Len Brown <len.brown@intel.com>
-------------------------------------------------------------
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
http://bugzilla.kernel.org/show_bug.cgi?id=9129
lenb: Note that overriding a critical trip point
may simply fool the user into thinking that they
have control that they do not actually have.
For it is EC firmware that decides when the EC
sends Linux temperature change events, and the
EC may or may not decide to send Linux these events
anywhere in the neighborhood of the fake
override trip points. Beware.
note also that thermal.nocrt is already available
to disable crtical trip point actios,
and thermal.crt=-1 is already available to
disabled critical trip points entirely.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
As of version 2.0, ACPI can return 64-bit integers. The current
acpi_evaluate_integer only supports 64-bit integers on 64-bit platforms.
Change the argument to take a pointer to an acpi_integer so we support
64-bit integers on all platforms.
lenb: replaced use of "acpi_integer" with "unsigned long long"
lenb: fixed bug in acpi_thermal_trips_update()
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Catch attempts to use of acpi_driver_data on pointers of wrong type.
akpm: rewritten to use proper C typechecking and remove the
"function"-used-as-lvalue thing.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'release-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-acpi-2.6:
acpi: fix crash in core ACPI code, triggered by CONFIG_ACPI_PCI_SLOT=y
ACPI: thinkpad-acpi: don't misdetect in get_thinkpad_model_data() on -ENOMEM
ACPI: thinkpad-acpi: bump up version to 0.21
ACPI: thinkpad-acpi: add bluetooth and WWAN rfkill support
ACPI: thinkpad-acpi: WLSW overrides other rfkill switches
ACPI: thinkpad-acpi: prepare for bluetooth and wwan rfkill support
ACPI: thinkpad-acpi: consolidate wlsw notification function
ACPI: thinkpad-acpi: minor refactor on radio switch init
Revert "ACPI: don't walk tables if ACPI was disabled"
Revert "dock: bay: Don't call acpi_walk_namespace() when ACPI is disabled."
Revert "Fix FADT parsing"
ACPI : Set FAN device to correct state in boot phase
ACPI: Ignore _BQC object when registering backlight device
ACPI: stop complaints about interrupt link End Tags and blank IRQ descriptors
We have the dev_printk() variants for this kind of thing, use them
instead of directly trying to access the bus_id field of struct device.
This is done in order to remove bus_id entirely.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Subject:ACPI: Set FAN device to correct state in boot phase
From: Zhao Yakui <yakui.zhao@intel.com>
On some laptops when ACPI FAN driver is loaded, maybe the FAN device will be
turned on. But if the temperature is below the threshold, the corresponding
FAN device should be turned off in the course of loading thermal driver.
So it is necessary to set the FAN device to the correct state in course of loading
the thermal driver.
http://bugzilla.kernel.org/show_bug.cgi?id=8049
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
My laptop thinks that it's a good idea to give -73C as the critical
CPU temperature.... which isn't the best thing since it causes a shutdown
right at bootup.
Temperatures below freezing are clearly invalid critical thresholds
so just reject these as such.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (179 commits)
ACPI: Fix acpi_processor_idle and idle= boot parameters interaction
acpi: fix section mismatch warning in pnpacpi
intel_menlo: fix build warning
ACPI: Cleanup: Remove unneeded, multiple local dummy variables
ACPI: video - fix permissions on some proc entries
ACPI: video - properly handle errors when registering proc elements
ACPI: video - do not store invalid entries in attached_array list
ACPI: re-name acpi_pm_ops to acpi_suspend_ops
ACER_WMI/ASUS_LAPTOP: fix build bug
thinkpad_acpi: fix possible NULL pointer dereference if kstrdup failed
ACPI: check a return value correctly in acpi_power_get_context()
#if 0 acpi/bay.c:eject_removable_drive()
eeepc-laptop: add hwmon fan control
eeepc-laptop: add backlight
eeepc-laptop: add base driver
ACPI: thinkpad-acpi: bump up version to 0.20
ACPI: thinkpad-acpi: fix selects in Kconfig
ACPI: thinkpad-acpi: use a private workqueue
ACPI: thinkpad-acpi: fluff really minor fix
ACPI: thinkpad-acpi: use uppercase for "LED" on user documentation
...
Fixed conflicts in drivers/acpi/video.c and drivers/misc/intel_menlow.c
manually.
Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.
Add correct ->owner to proc_fops to fix reading/module unloading race.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the problem that thermal_get_temp returns the cached value,
which causes the temperature in generic thermal never updates.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Update the documentation for the thermal driver hwmon sys I/F.
Change the ACPI thermal zone type to be consistent with hwmon.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Add a new callback so that the generic thermal can get
the critical trip point info of a thermal zone,
which is needed for building the tempX_crit hwmon sysfs attribute.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Len Brown <len.brown@intel.com>
drivers/acpi/thermal.c: In function 'acpi_thermal_init':
drivers/acpi/thermal.c:1794: error: 'thermal_dmi_table' undeclared (first use in this function)
drivers/acpi/thermal.c:1794: error: (Each undeclared identifier is reported only once
drivers/acpi/thermal.c:1794: error: for each function it appears in.)
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
thermal_zone_device_register() uses the ERR_PTR macro on its return values. A
correct check is to use the IS_ERR() macro.
The 2.6.25 kernels panic on Compaq AP550 without this patch as it has more
then 10 (THERMAL_MAX_TRIPS) trip points (there are 12).
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
as now required by the generic thermal I/F
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Len Brown <len.brown@intel.com>
The alias name may be used in _PSL, _ALx and _TZD,
so we bind the cooling device only if the acpi_device node matches.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Thomas Sujith <sujith.thomas@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Fix an imprecision in CELSIUS_TO_KELVIN and move these
two macroes to a proper place.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Thomas Sujith <sujith.thomas@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Intel menlow driver needs to get the pointer of themal_zone_device
structure of an ACPI thermal zone.
Attach this to each ACPI thermal zone device object.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Thomas Sujith <sujith.thomas@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Change the ACPI thermal action upon notification 0x81 and 0x82.
According to the ACPI spec, we should:
re-evaluate _PSV and _ACx methods upon notification 0x81
re-evaluate _PSL and _ALx and _TZD upon notificaiton 0x82.
But the current code re-evaluates all the trip points for 0x81 while
only re-evaluates _TZD for 0x82.
Fix this violation of ACPI spec.
TODO: devices in _PSL, _ALx and _TZD may change after a notification 0x82.
At this time, we need to re-bind the cooling devices with the thermal zone.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Thomas Sujith <sujith.thomas@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Register ACPI thermal zone as thermal zone device.
the new sys I/F for ACPI thermal zone will be like this:
/sys/class/thermal:
|thermal_zone1:
|-----type: "ACPI thermal zone". RO
|-----temp: the current temperature. RO
|-----mode: the current working mode. RW.
the default value is "kernel" which means thermal
management is done by ACPI thermal driver.
"echo user > mode" prevents all the ACPI thermal driver
actions upon any trip points.
|-----trip_point_0_temp: the threshold of trip point 0. RO.
|-----trip_point_0_type: "critical". RO.
the type of trip point 0
This may be one of critical/hot/passive/active[x]
for an ACPI thermal zone.
...
|-----trip_point_3_temp:
|-----trip_point_3_type: "active[1]"
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Thomas Sujith <sujith.thomas@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
module parameter is used to prevent the thermal_zone action upon
critical trip points.
But exporting this notification to userspace is still useful.
By setting nocrt with this patch applied, ACPI will take no action
but exporting the events to userspace upon critical/hot trip points.
http://bugzilla.kernel.org/show_bug.cgi?id=9139
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (41 commits)
ACPICA: hw: Don't carry spinlock over suspend
ACPICA: hw: remove use_lock flag from acpi_hw_register_{read, write}
ACPI: cpuidle: port idle timer suspend/resume workaround to cpuidle
ACPI: clean up acpi_enter_sleep_state_prep
Hibernation: Make sure that ACPI is enabled in acpi_hibernation_finish
ACPI: suppress uninitialized var warning
cpuidle: consolidate 2.6.22 cpuidle branch into one patch
ACPI: thinkpad-acpi: skip blanks before the data when parsing sysfs
ACPI: AC: Add sysfs interface
ACPI: SBS: Add sysfs alarm
ACPI: SBS: Add ACPI_PROCFS around procfs handling code.
ACPI: SBS: Add support for power_supply class (and sysfs)
ACPI: SBS: Make SBS reads table-driven.
ACPI: SBS: Simplify data structures in SBS
ACPI: SBS: Split host controller (ACPI0001) from SBS driver (ACPI0002)
ACPI: EC: Add new query handler to list head.
ACPI: Add acpi_bus_generate_event4() function
ACPI: Battery: add sysfs alarm
ACPI: Battery: Add sysfs support
ACPI: Battery: Misc clean-ups, no functional changes
...
Fix up conflicts in drivers/misc/thinkpad_acpi.[ch] manually
Three main sets of changes:
1) dmi_get_system_info() return value should have been marked const,
since callers should not be changing that data.
2) const-ify DMI internals, since DMI firmware tables should,
whenever possible, be marked const to ensure we never ever write to
that data area.
3) const-ify DMI API, to enable marking tables const where possible
in low-level drivers.
And if we're really lucky, this might enable some additional
optimizations on the part of the compiler.
The bulk of the changes are #2 and #3, which are interrelated. #1 could
have been a separate patch, but it was so small compared to the others,
it was easier to roll it into this changeset.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Fix for #3686, where get_temperature() may cause thermal notify, which
causes one more get_temperature().
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Properly functioning systems do not use thermal zone polling,
they use event-based notification.
However, some users enable periodic thermal zone polling
to work around bugs on their platforms, and at least one
platform exists with a real _TZP that requests polling.
While thermal zone polling (_TZP) is specified in units to 0.1 seconds,
it actually has a maximum granularity of 1 second. Thus, we can safely
round up the _TZP timeout to occur on the next 1-second boundary.
This will batch it with other 1-second-granularity timers in the
system and thus potentially extend processor idle duration.
Note that the same timer is used both for _TZP
and for passive processor thermal throttling.
We can not round up the timeout when it is used
for passive thermal throttling.
Also, we can not make this a deferrable timer,
as temperature is just as relevant during idle
as it is during non-idle.
Signed-off-by: Len Brown <len.brown@intel.com>
Schedule /proc/acpi/event for removal in 6 months.
Re-name acpi_bus_generate_event() to acpi_bus_generate_proc_event()
to make sure there is no confusion that it is for /proc/acpi/event only.
Add CONFIG_ACPI_PROC_EVENT to allow removal of /proc/acpi/event.
There is no functional change if CONFIG_ACPI_PROC_EVENT=y
Signed-off-by: Len Brown <len.brown@intel.com>
The previous events patch added a netlink event for every
user of the legacy /proc/acpi/event interface.
However, some users of /proc/acpi/event are really input events,
and they already report their events via the input layer.
Introduce a new interface, acpi_bus_generate_netlink_event(),
which is explicitly called by devices that want to repoprt
events via netlink. This allows the input-like events
to opt-out of generating netlink events. In summary:
events that are sent via netlink:
ac/battery/sbs
thermal
processor
thinkpad_acpi dock/bay
events that are sent via input layer:
button
video hotkey
thinkpad_acpi hotkey
asus_acpi/asus-laptop hotkey
sonypi/sonylaptop
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Some hardware will malfunction at a temperature below
the BIOS provided critical shutdown threshold.
This hook allows moving the critical trip points down
to a temperature which provokes a graceful shutdown
before the hardware malfunction.
http://bugzilla.kernel.org/show_bug.cgi?id=8884
WARNING: A trip-point override will not get noticed
until the system delivers a temperature change event,
or unless thermal zone polling is enabled.
eg. "thermal.tzp=10"
Signed-off-by: Len Brown <len.brown@intel.com>
Use DMI to:
1. enable polling (BIOS thermal events are broken)
2. disable active trip points (BIOS fan control is broken)
3. disable passive trip point (BIOS hard-codes it too low)
The actual temperature reading does work,
and with the aid of polling, the critical
trip point should work too.
http://bugzilla.kernel.org/show_bug.cgi?id=8842
Signed-off-by: Len Brown <len.brown@intel.com>
thermal.act=-1 disables all active trip points
in all ACPI thermal zones.
thermal.act=C, where C > 0, overrides all lowest temperature
active trip points in all thermal zones to C degrees Celsius.
Raising this trip-point may allow you to keep your system silent
up to a higher temperature. However, it will not allow you to
raise the lowest temperature trip point above the next higher
trip point (if there is one). Lowering this trip point may
kick in the fan sooner.
Note that overriding this trip-point will disable any BIOS attempts
to implement hysteresis around the lowest temperature trip point.
This may result in the fan starting and stopping frequently
if temperature frequently crosses C.
WARNING: raising trip points above the manufacturer's defaults
may cause the system to run at higher temperature and shorten
its life.
Signed-off-by: Len Brown <len.brown@intel.com>
thermal.nocrt=1 disables actions on _CRT and _HOT
ACPI thermal zone trip-points. They will be marked
as <disabled> in /proc/acpi/thermal_zone/*/trip_points.
There are two cases where this option is used:
1. Debugging a hot system crossing valid trip point.
If your system fan is spinning at full speed,
be sure that the vent is not clogged with dust.
Many laptops have very fine thermal fins that are easily blocked.
Check that the processor fan-sink is properly seated,
has the proper thermal grease, and is really spinning.
Check for fan related options in BIOS SETUP.
Sometimes there is a performance vs quiet option.
Defaults are generally the most conservative.
If your fan is not spinning, yet /proc/acpi/fan/
has files in it, please file a Linux/ACPI bug.
WARNING: you risk shortening the lifetime of your
hardware if you use this parameter on a hot system.
Note that this refers to all system components,
including the disk drive.
2. Working around a cool system crossing critical
trip point due to erroneous temperature reading.
Try again with CONFIG_HWMON=n
There is known potential for conflict between the
the hwmon sub-system and the ACPI BIOS.
If this fixes it, notify lm-sensors@lm-sensors.org
and linux-acpi@vger.kernel.org
Otherwise, file a Linux/ACPI bug, or notify
just linux-acpi@vger.kernel.org.
Signed-off-by: Len Brown <len.brown@intel.com>
"thermal.psv=-1" disables passive trip points
for all ACPI thermal zones.
"thermal.psv=C", where 'C' is degrees Celsius,
overrides all existing passive trip points
for all ACPI thermal zones.
thermal.psv is checked at module load time,
and in response to trip-point change events.
Note that if the system does not deliver thermal zone
temperature change events near the new trip-point,
then it will not be noticed. To force your custom
trip point to be noticed, you may need to enable polling:
eg. thermal.tzp=3000 invokes polling every 5 minutes.
Note that once passive thermal throttling is invoked,
it has its own internal Thermal Sampling Period (_TSP),
that is unrelated to _TZP.
WARNING: disabling or raising a thermal trip point
may result in increased running temperature and
shorter hardware lifetime on some systems.
Signed-off-by: Len Brown <len.brown@intel.com>
Thermal Zone Polling frequency (_TZP) is an optional ACPI object
recommending the rate that the OS should poll the associated thermal zone.
If _TZP is 0, no polling should be used.
If _TZP is non-zero, then the platform recommends that
the OS poll the thermal zone at the specified rate.
The minimum period is 30 seconds.
The maximum period is 5 minutes.
(note _TZP and thermal.tzp units are in deci-seconds,
so _TZP = 300 corresponds to 30 seconds)
If _TZP is not present, ACPI 3.0b recommends that the
thermal zone be polled at an "OS provided default frequency".
However, common industry practice is:
1. The BIOS never specifies any _TZP
2. High volume OS's from this century never poll any thermal zones
Ie. The OS depends on the platform's ability to
provoke thermal events when necessary, and
the "OS provided default frequency" is "never":-)
There is a proposal that ACPI 4.0 be updated to reflect
common industry practice -- ie. no _TZP, no polling.
The Linux kernel already follows this practice --
thermal zones are not polled unless _TZP is present and non-zero.
But thermal zone polling is useful as a workaround for systems
which have ACPI thermal control, but have an issue preventing
thermal events. Indeed, some Linux distributions still
set a non-zero thermal polling frequency for this reason.
But rather than ask the user to write a polling frequency
into all the /proc/acpi/thermal_zone/*/polling_frequency
files, here we simply document and expose the already
existing module parameter to do the same at system level,
to simplify debugging those broken platforms.
Note that thermal.tzp is a module-load time parameter only.
Signed-off-by: Len Brown <len.brown@intel.com>
"thermal.off=1" disables all ACPI thermal support at boot time.
CONFIG_ACPI_THERMAL=n can do this at build time.
"# rmmod thermal" can do this at run time,
as long as thermal is built as a module.
WARNING: On some systems, disabling ACPI thermal support
will cause the system to run hotter and reduce the
lifetime of the hardware.
Signed-off-by: Len Brown <len.brown@intel.com>
modpost is going to use these to create e.g. acpi:ACPI0001
in modules.alias.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Various pieces of code around the kernel want to be able to trigger an
orderly poweroff. This pulls them together into a single
implementation.
By default the poweroff command is /sbin/poweroff, but it can be set
via sysctl: kernel/poweroff_cmd. This is split at whitespace, so it
can include command-line arguments.
This patch replaces four other instances of invoking either "poweroff"
or "shutdown -h now": two sbus drivers, and acpi thermal
management.
sparc64 has its own "powerd"; still need to determine whether it should
be replaced by orderly_poweroff().
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Len Brown <lenb@kernel.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David S. Miller <davem@davemloft.net>
if acpi_bus_get_device() returns NULL, print nothing
instead of "<NUL" in /proc/acpi/thermal_zone/*/trip_points
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
For users with active thermal trip points, they need
the fan's name, rather than its address, to understand
where to look to observe and control fan state.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
